Process of making isobornyl esters.



TJNITED STATES PiFENT oFFIoE- CHARLES WEIZMANN, or RU-SHOLME, MANCHESTER, ENGLAND, ASSIGNOR To THE CLAYTOI ANILINE COMPANY, LIMITED, or CLAYTON, ENGLAND. I

r'aoess's or MAKING IsoBoRnYL ESTERS.

To all whom it may concern", 7

Be it known that I, CHARLES WEIZMANN, of Rushohne, Manchester, England, have invented certain new and useful Improvements in the h lanulacture of Isobornyl Esters, of which the following is a specification.

The processes which hitherto have been considered most successful for the manufacture ofisobornyle'sters are either double decomposition between pinene hydrochlorid and a salt ofone of the heavy metals, such as zinc, or lead, on catalytic action of'a zinc compound on a boiling mixture of pinene hydrochlorid and a iattyvacid, but these processes have the disadvantage that-a considerable amount of resinous matter is .formed, and, as this is of much less value than isobornyl acetate, the formation of such resinous matter is a serious objection to the processes, and it is the object of this invention to overcome this objection. j

According to this invention a mixture of pincne hydrochlorid and a fatty acid is boiled, or heated to a suitable temperature, in the presence of metallic zinc (preferably in a line state of division) whereby a product is obtained consisting mainly of isobornyl ester free, or practically free, from resinous matter. This result was not to be anticipated because zinc in the presence of fatty acid is known to exert a powerful reducing action on halogen organic compounds, and

herefore it was to be presumed that the SllbStiHlUOS which would be produced would be such reduction products as camphane, dicamphyl, or similar reduction products instead of the product which I obtain.

The following is an example of the manner in-which this invention may be carried-into effect, but I do not limit myself to this example. Theparts are by weight. A mixture of 100 parts of pinenc hydrochlorid,

' 300 parts ol" glacial acetic acid, and 30 parts of zinc dust, is gently boiled in a reflux apparatus, or heated. on a boiling water bath, until a sample of the mixture (after making: it alkaline with caustic soda) yields an oil f ee from chlorin, this generally being the case after about 20 hours boiling or heating; The excess of acetic acid is then ren'iovcd by distillation of the product of rcactionunderreduced pressure at 40 centigrade and 15 mm and the isobornylacetate is separated Specification of Letters Patent.

Application filed March 5, 1908. Serial No. 419,246.

Patented 39.1 26, 1909.

by pouring the residual oil into water; crude isobornylacetate separates out, which is decanted and redistilled' under reduced pressure at a temperature of 100 to 120 at 15 mm. to

18 mm'., (mm. indicating millimeters.)

The probable course of the reaction is the following: The metallic zinc removes in the first instance hydrochloric acid from the pinene hydrochlorid and forms camphene.

v yields isobornylacetate Isobornylacetate The superiority of the yield is evident from the followingfacts: I obtain by the method herein described, a yield amounting to 72% to 75% of the theory, starting frorn'pinenehydrochlorid, which is a technical product and by no means chemically pure; whereas by the other methods the yield is 65% to 66% of theory. The better ield is due to the fact that, in taking metal ic zinc, no water is formed during the reaction and the hydrogen, which is evolved during the process prevents'oxidation, consequently also resiniiication of the product. I claim:

1. The process of manufacturing isobornylesters, the herein described steps, to wit:

heating a mixture of pineneh drochlorid and fatty acids in the presence o metallic zinc.

' 2. The manufacture of isobornylesters by In tstimony whereof I have affixed my digesting a'mjxture of pinenehydrochlorid signature, in presence of two Witnesses.

and fiattgf'acida with getallichzmc; 2 sm 0,-mixtureaer ma'nga a'e yiel s an oil free from chlorin, then distilling 1 CHARLES WEIZMANN 5 05 the acetic acid, WsLshing the oil and frac- Witnesses:

tiomting the crude isobemylester under re- ERNALD SIMPSON Mommy, duced pressure. I MALCOLM SMETHms'r. 

